FIGS. 1 and 2 detail a semiconductor fabrication facility according to the prior art. The fabricator 20 forms circuit patterns on semiconductor wafer substrates according to preprogrammed instructions.
The fabricator 20 in this example is a Rainbow.TM. model 4400/4500 available from Lam Research of Fremont, Calif. The fabricator is constructed to include a "front end" 22 and a "back end" 24. The front end 22 (FIG. 1) is defined by an upstanding wall 26 that can include various transparent windows formed of glass, plexiglass or another transparent material. The front end 22 typically fronts on a clean room having a predefined level of environmental control. Similarly, the back end 24 is located in a clean room often having a different level of environmental control. The semiconductor fabrication mechanism 28 (FIG. 2) resides in the back end 24. Within the back end is contained an loadlock mechanism 30 for holding and transferring semiconductor wafers in a clean environment. A pneumatic tray assembly 32 transfers wafers into and out of the loadlock 30. A pneumatic regulator assembly 34 controls the action of the tray assembly 32.
Semiconductor wafers are processed by etching, deposition and other techniques in the process chamber 36. A manometer 38 regulates pressure within the process chamber 36, which is typically kept at a near-vacuum. A valve assembly 40 controls the atmosphere within the chamber 36. Operators interact with the fabricator 20 through the front end (FIG. 1). Semiconductor wafers are loaded for process into a send indexer 42. Likewise, processed semiconductor wafers are removed through a receive indexer 44. The individual semiconductor wafers 48 and 50 are held in the indexers 42 and 44, respectively in stacks. Power switching and other basic fabricator functions are operated via the front control panel 52. Data related to process parameters and other specific process functions is input and displayed through the operator interface control panel 54 which includes a display screen 56 and data entry buttons 58. Data, in the form of text and graphics is manipulated on the screen 56 using the buttons 58. A conventional cursor is provided on the screen.
The operator interface control panel 54 utilizes a well-known XYCOM.RTM. format industrial dedicated terminal available from XYCOM, Inc. Saline, Mich. The XYCOM.RTM. terminal acts as a so-called "dumb" in that it contains in its chassis 62 (FIG. 2) only minimal data processing and recognition capabilities and, rather, directly transmits and receives character and graphic data from the fabricator's central processing unit 64 through a data line 66 (shown in phantom). A terminal communications driver 53 of conventional design that is compatible with the XYCOM.RTM. data format. The control panel 54 is accessible only from the front end of the fabricator. Since the wall 26 separates the front end 22 from the back end 24, an operator on the back end cannot readily access the control panel 54. Accordingly, an optional data connection 70 is provided on the fabricator within the back end space. It is tied to the central processing unit 64 by a cable 69. The connector can comprise any acceptable style of connector, such as an RS232 standard connector. This connector enables interconnection of a data line 72 with another optional control panel 74 that is somewhat portable. This control panel 74 is kind of itself, a XYCOM.RTM. terminal mounted on a wheeled stand 76. The central processing unit 64 is design to recognize inputs from either the connector 70 or the front end control panel 54 and to respond to such inputs with operations and display data. Like the control panel 54, the portable control panel 74 includes a data screen 78 and data input buttons 80 and acts as a so-called dumb terminal, relying upon the data processing capabilities of the central processing unit 64 and driver 53 for display and interpretation of input data.
Since the front end 22 and back end 24 are separated by the wall 26, and typically, entire row of fabricators are provided side-by-side, it is not easy for an operator to move from the front end to the back end. This often necessitates the use of several portable control panels 74 within the back end space. These control panels are bulky and difficult to move about. They take up highly valuable floor space on the fabrication clean room floor. They are also expensive, owing to their size, uniqueness and specialized hardware such as a cart. Parts are not readily available for such specialized terminals and will become less available as terminals become obsolete. These control panels block the path of operators moving between fabricators and, in general, reduce productivity.
It is, therefore, an object of this invention to provide a substitute data-entry and display device for accessing the central processing unit of a semiconductor fabricator. This device should be readily available, highly portable and should occupy minimal floor space. The device can also be readily adaptable to augment or replace the front end control panel of a semiconductor fabricator.